The objective of this project is to determine factors controlling synthesis, interrelationships and catabolism of the major lipoproteins in the plasma space. Emphasis is placed on the study of very low density, low density and high density lipoproteins. This objective will be pursued in several ways. Lipoprotein turnover and chemical cholesterol balance will be performed in patients with cellular defects in lipid metabolism discovered in cultured fibroblasts. Cellular biochemical derrangements will be related to alterations in lipoprotein physiology. Patients from families with autosomal dominant forms of familial hyperlipidemias will participate in lipoprotein turnover and chemical cholesterol balance to describe the pathophysiology of these diseases. Normal lipoprotein physiology will be related to cholesterol balance in the baboon using a variety of dietary formulas and medications to more fully understand the factors influencing lipoprotein transport in plasma.